According to a U.S. tax court filing, first obtained by Bloomberg, the IRS says Redstone owes $1.1 million in back taxes, penalties and interest from a series of unreported taxable gifts to his family in 1972.

More than four decades later, the IRS wants its money -- saying that Redstone failed to file a return after giving stock in the family’s National Amusements Inc. to his son and daughter.

In a petition filed April 10, Redstone disputes the notion that the stocks were a gift, arguing instead that the exchange was an "ordinary business transaction" stemming from the settlement of a family lawsuit.

Reached for comment, David Andelman, an attorney with the law firm Lourie & Cutler who represents Redstone, refused to elaborate. “I think the petition speaks for itself,” he said.

A spokesman for Viacom also declined to comment, other than to note that Redstone’s “The Partridge Family”-era tax woes had "no bearing" on the company.